The invention relates to compounds, of formula (I) in which X is CH3 or hydrogen, Z is a linear or branched C2 to C4 alkyl radical, R is a linear or branched, optionally heteroatom-substituted aliphatic, aromatic or araliphatic radical, Y in each occurrence is independently hydrogen, methyl, ethyl, propyl, n-butyl, tert-butyl, chlorine, bromine, iodine, methylthio, phenyl or phenylthio, n is from 0 to 4 and m is from 0 to 5. The invention further relates to the use of such a compound as writing monomer in a photopolymer formulation. In addition, a photopolymer formulation comprising as least a polyisocyanate component, a polyol component, a photoinitiator and a compound of formula (I) as writing monomer, and also the use of the photopolymer formulation for producing holographic media, are likewise subjects of the invention.